Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Investigation of A2 allele frequency in Taiwanese Holstein cattle using genetic testing

100%

Chao C. H., Shiau J. W.

Polish Journal of Veterinary Sciences

2025

tom 28

nr 2

β-Casein accounts for approximately 30% of total milk protein, with the A1 and A2 variants being the most common. A1 β-casein may release β-casomorphin-7 (BCM-7) during digestion, which is associated with adverse health effects, whereas A2 β-casein does not. This study investigated the A2 allele frequency and its potential influence on milk performance in Holstein cattle in Taiwan. A total of 1,050 cows from five herds were genotyped using the GeneSeek 50K SNP chip. The A2 allele frequency ranged from 0.58 to 0.75 among herds, with an average of 0.66. Hardy-Weinberg equilibrium tests indicated no significant deviation within herds. Pedigree validation confirmed Mendelian inheritance of A1 and A2 alleles. Furthermore, 348 cows with complete lactation records were evaluated for 305-day mature equivalent milk and fat yields across genotypes. Although cows with the A1/A1 genotype showed numerically higher milk and fat yields, one-way ANOVA and Tukey’s HSD tests revealed no statistically significant differences. These results suggest that while A2 allele selection is increasing in Taiwan, β-casein genotype does not significantly influence milk or fat production in the studied population.

Sire pedigree error estimation and sire verification of the Taiwan dairy cattle population by using SNP markers

61%

Chao C. H., Yeh Y. H., Chen Y. M., Lee K. H., Wang S. H., Lin T. Y.

Polish Journal of Veterinary Sciences

2022

tom 25

nr 1

Information regarding the correct pedigree of and relationship between animals is useful for managing dairy breeding, reducing inbreeding, estimating breeding value, and establishing correct breeding programs. Additionally, the successful implementation of progeny testing is crucial for improving the genetics of dairy cattle, which depends on the availability of correct pedigree information. Incorrect pedigree information leads to bias in bull evaluation. In this study, Neogen GeneSeek Genomic Profiler (GGP) 50K SNP chips were used to identify and verify the sire of Taiwanese Holstein dairy cattle and analyze the reasons that lead to incorrect sire records. Samples were collected from 2,059 cows of 36 dairy farms, and the pedigree information was provided by breeders. The results of sire verification can be divided into three categories: submitted unconfirmed sire, submitted confirmed sire, and incorrectly submitted verified sire. Data on the sires of 1,323 (64.25%) and 572 (27.78%) dairy cows were verified and discovered, respectively. Sires of 1,895 (92.03%) dairy cattle were identified, which showed that the paternal pedigree of dairy cattle could be discovered and verified through genetic testing. An error-like analysis revealed that the data of 37 sires were incorrectly recorded because the bull’s NAAB code number was incorrectly entered into the insemination records: for 19 sires, the wrong bull was recorded because the frozen semen of a bull placed in the wrong storage tank was used, 6 had no sire records, and for 12 sires, the NAAB code of the correct bull was recorded but with a wrong stud code, marketing code, or unique number for the stud or breed. To reduce recorded sire error rates by at least 27.78%, automated identification of the mated bull must be adopted to reduce human error and improve dairy breeding management on dairy farms.

Ograniczanie wyników

2 Polish Journal of Veterinary Sciences

2 Chao C. H.

1 Chen Y. M.

1 Lee K. H.

1 Lin T. Y.

1 Shiau J. W.

1 Wang S. H.

1 Yeh Y. H.

1 2025

1 2022

Wyniki wyszukiwania

Investigation of A2 allele frequency in Taiwanese Holstein cattle using genetic testing

Sire pedigree error estimation and sire verification of the Taiwan dairy cattle population by using SNP markers